Insulating-piston for steam-engines.



P. A. PRITSCHAU. INSULATING PISTON FOR STEAM ENGINES. APPLICATION FILLED MAR.12, 1909.

gggggg gg Patented June :15, 1909.

- armed June To all wiz T01? and. its firnnsm V, V f .1 Eu 1t 1 us How (3mm 1,

03* the an 6G nlsists in the f as iihzsira'ted. in the a 1 diam 11 acmnia 3 302; a. invars iiw 0 7G :1 bsorbing pri $91 which emptied after starce an 2 a p .,9 rom t" died. ini he.

imust,

The 611mg 7 2a fihe live a L {j ,j

31 0 the axhn c-(msinlera is per Mimi-Ute to the synmlez' that in the 3G rt on 7 of a. 1 YOU! 8 m'ticzl 'Z im Ulla en- 19: 3 This loss ant suiting from film ricai portion cyhnder Willis, ai li e hub,

35 der that is .650 amt. ea i0 has little 01-110 arises from the )s 11W steam and i i is pro- 120 the exhaust, by th j v1. annular piston far steam conductivity, sorption as se't mum, and with l5 vention braadiy semis-W sme areas of PM M conduc 'tix .ty, wh h on becomes raised to t Lb and. 021 119 or active sezun, 0 L T19 5 such temperaiure, d 0': are of isi- 105 by the sudden dro; e c steam due to Rs z'eie pr whereby the energ "-i the bed" i, and bu; 1d messed body stenm is ItdUC-(Td bui portion? it 1 the mm partio 8 abutting 55 sta 31a 2 0. t r ks are of ,0

of heat from 312 slightly less diameter than the rim of the body 1 of the piston, and the outer faces of the disks are slightly rounded into the peripheries of the disks. The disks l6 areprovided' with bolt holes 19 to receive the end portions15 of the rivet bolts 14, and the holes 3 Z the character of the material permits of their 19 are countersunk at the outer sides of tho disks to receive the rivet heads 20 formed thereon after the disks are mounted on the body of the piston. in Fig. l l have shown the disks 16 formed of ,jlilSS,"-Dl(?fCl'itblY either toughened, wire, or quartz glass,-and where glass is used I prefer to provide thin Outer plates 21 and 21 of sheet metal, press drawn and cup shaped, to fit over and receive the outer portions of the disks and extend over their peripheries, and between the disks and the body of the piston, and be tween the disks and the caps, are interposed thin sheets of asbestos or the like, to form cushions for the glass. The joints between should also be filled with cement to render them impervious to steam. The plate 21 is provided "with an enlarged. axial orifice of a diameter to receive the piston rods, and is 5 also centrally secured by a collar 23, shrunk or otherwise secured on the piston.

While the protecting plates 21 and 21, by reason of their conductivity, lesson in some degree the efficiency of the disks 16, the thinness of the plates limits their mipacity of ahj sorptlon and the number oi units of heat that are lost through their use is small as compared with the loss that occurs from the naked piston.

In Fig. 2, the piston body 1 shown pro-- vided with disks 16 of compressed :libcr, of wood, asbestos, etc., which are of like form as the glass disks shown in Fig. l. liowever, for disks of this or any other mater al,

the plates 21 and 21 may be omitted, wnere use without protecting plates.

By equipping, a piston with low conductive disks or coverings as described, the power and elllcieney of the engine is increased, and the loss of energy due to the substantially (continuous absorption of heat from the live steam and its return or transference to the exhaust steam, by the piston, is reduced to a minimum.

It is manifest that the principle of construrtion herein desrribed, may be advantageously applied to pistons of other heat niotors, and 1 therefore donotliniit myself to its application to pistons of steam engines only.

rlflhat I claim to be new is- 1. In a piston for steam engines and the like, the combination with the metallic body of the piston, of low conductive coverings for the pressure areas of the body, substantially as and for the purpose set forth.

2. In a piston 'for steam. engines and the 1 like, the combination with the metallic body of the piston, of disks composed. of low conduetive material and covering the pressure faces of the :iiston body, substantially as and. for the purpose set forth.

3. in a piston for steam engines and the like, the combination with the metallic body of the piston, l.' low conductive disks, secured to and covering the u'essure faces of the body, said disks being provided with sheet metal protecting caps, substantially as and for the purpose set forth.

in witness whereof I have hereunto signed my name in the presence of two subscribing \x'itnesses, this 4 h day of March, 1909.

.hifli lNANl) A. PitilSOHAU. in presence of* 

